James Hardie is, without a doubt, the superior exterior siding brand in today’s market, covering 8 million homes and counting. However, James Hardie can only perform as well as it’s installer. That is why the team at Burr Roofing, Siding, & Windows follows the Installation Best Practices Guide to a T. This comprehensive manual details each step of the installation process, coming together in a 132-page document. In order to receive the full benefits of Hardie’s 30-year warranty, the siding must be expertly installed by the book.
Roofline clearance is a vital part of correct installation. Due to the volume of water that can run down a sloped roof, one of the most critical flashing details is where the roof intersects with a sidewall. At this junction, there must be a self-healing adhesive backed membrane along the roof to sidewall, installed before the flashing. The roof is then flashed to the wall with 16 oz. copper step flashing positioned at every shingle course. We also install a kickout flashing to deflect water away from the siding. Kickout flashing is made by cutting and bending a piece of step flashing at an angle. The water-resistant barrier is then lapped over the step flashing and the roofline to sidewall intersection is 100% waterproofed.
Without proper installation practices, your brand-new James Hardie will fail prematurely, throwing your investment out with the trash. Here are some the Hardie roofline fails we have encountered over the years:
This is a great example of what can happen if your installer does not follow the James Hardie manual. This homeowner hired a different contractor to install James Hardie clapboard 6 years prior to Burr visiting the property. In just 6 years, the siding had completely failed, leaving the ColorPlus finish looking like this. If the installer had used the correct roofline clearance, this could have been avoided.
Although there does seem to be some step flashing here, the Hardie has still started to fail. The roofline clearance must be 2″ wide and continuous across the entire roof to sidewall area. At Burr Roofing, Siding, & Windows we make sure that all roof to sidewall junctions have a 2″ strip of aluminum, protecting your siding from premature failure.
Here, you can see the complete lack of roofline flashing, causing the first two courses of Hardie to fail at the bottom of the roofline. If this is not remedied, this failure will continue up the entire roof to sidewall junction.
This is what a roofline clearance should look like. The Burr team installed a 2″ piece of aluminum flashing between the James Hardie siding and roof shingles, ensuring the longevity of this install. Due to proper installation, this home will be beautiful for years to come!